Types & Fundamentals:Power SourcesThe two main power sources for powered industrial trucks
are internal combustion, which uses a traditional engine that runs on liquid
petroleum gas (LPG), compressed natural gas (CNG), gasoline, diesel, or
other fuel, and electric, which uses an on-board battery. This section provides
information on these power sources, including some of the potential hazards and
possible solutions associated with their use and with refueling and battery
charging/changing operations.

Other power sources that may become more widespread in the future include fuel
cells and hybrid systems. Hydrogen fuel cells will have zero emissions and quiet
operation plus the ability to be refueled as quickly as gasoline engines. Hybrid
systems will use a combination of fuel cells and batteries.